MACHINE MEASURES OF FAT MASS AND FAT DISTRIBUTION
Technological developments in the area have led to a number of different machines now being available for directly or indirectly measuring body fatness. Some of these are extremely expensive and would not be used in the normal day-to-day counseling situation. Others are now becoming more portable and more accessible and provide at least an opportunity for adding to other measures. The current range of machines include: underwater weighing, bio-impedance analysis, etc.
Bio-impedance analysis (BIA). BIA, which measures body fatness through electrical conductivity of body tissue, was introduced in the 1980s. A tiny imperceptible current travels through the water compartment of the body, which is proportional to the fat-free mass (FFM), there being very little water in fat. The more FFM, the more current is conducted. The impedance (or resistance to electical flow) is then put into an equation in the BIA machine to calculate the percentage of body fat. BIA machines are now small and portable and usually involve the wiring of electrodes onto the limbs of the body. The electrical current is slight and nothing is felt by the person being tested.
New developments have now led to BIA measures being combined with ordinary weight scales. By standing on the scales an undetectable electric current is passed through the soles of the feet and a measure of body fat is computed along with body weight. The combination of the two provides an increased diagnostic potential. A good deal of research has been earned out with BIA and comparisons with other measures such as near infrared analysis (NIR, see below) and other criterion measures. Indications are that BIA is significantly affected by fluid content of the body, and although reasonably valid, has a low reliability if not measured under similar conditions on each occasion.
*68\186\4*
Random Posts
Leave a Reply
Please use theregistration to leave a Reply